1. Field of the Invention
The present invention relates to a surgical dissector. More particularly, the present invention relates to a dissector useable in the performance of surgical procedures on spongy organs made of pulpy, friable tissue, through which course blood vessels and ducts of various sizes. The invention is particularly adapted to the partial resectioning of a kidney, however it is also useful in the performance of nephrotomies, hepatectomies and pancreatectomies.
2. Brief Discussion of the Related Art
Surgical operations on spongy organs made of pulpy, friable tissues through which course blood vessels and ducts introduce unique problems, particularly where it is necessary to resection the organs without excessive bleeding from the blood vessels or other discharge from the ducts. It is therefore desirable to be able to identify and individually ligate the blood vessels and other ducts after incisions into the organ. Conventionally, this has been found to be difficult, and as a result such blood vessels and other ducts were cut with accompanying bleeding and fluid loss. Mass suture ligation of tissue was then necessary for hemostasis.
An effort to solve this problem has been described in Tien-Yu Lin, "A Simplified Technique for Hepatic Resection. The Crush Method", Annals of Surgery 180: 285-290, 1974. Lin describes a hepatic libectomy which uses a liver crush clamp to fracture the friable liver tissue using a "crush method." A liver crush clamp in the form of a scissors having short teeth on one of its jaws was tightly applied to the liver near the intended position of an incision line. After incision, the clamp was introduced into the rent liver and repeatedly tightly applied in order to crush liver tissue after which the crushed liver tissue was removed, leaving the hepatic artery, portal vein branches and hepatic duct exposed. Following ligation of the exposed tissue, the affected lobe was detached and the clamp loosened. In a partial resection of a liver, the unyielding vascular and ductile components appear as cord-like bridges connecting two parts of the liver, following a crushing operation, and they are individually ligated and divided.
However, the Lin clamp has certain deficiencies, particularly if used for surgical operations on a relatively thick organ such as a kidney. For example, in resectioning any spongy organ, the Lin clamp will apply pressure unevenly along the length of the scissors jaws. The scissors jaws will close more fully, and so apply greater pressure, near their joint than at their mid-point. As a result, blood vessels or other ducts closest to the scissors joint can be crushed and damaged while friable organ tissue further from this joint may not be sufficiently crushed to expose the blood vessels therein. Moreover, the relatively sharp teeth on one of the scissors jaws of the Lin clamp can puncture or further damage blood vessels. This can result in the aforementioned undesirable blood loss.
This problem is accentuated in a kidney resectioning due to the fact that the kidney is a relatively short and thick organ. The scissors-like action of the Lin clamp produces an even greater angling between the scissors jaws in the resectioning of such thick organs, so that pressure and closure degree differentials along the length of the jaws are increased and the likely damage to blood vessels, both due to this pressure/closure differential and to damage from the sharp teeth of the clamp, is increased.